Hinge construction for box and cover



Feb. 22, 1966 E. J, MCFADDEN ETAL 3,236,408

HINGE CONSTRUCTION FOR BOX AND COVER Filed Feb. 13, 1964 J5 JazwmJfJ/aUnited States Patent 3,236,408 HINGE CONSTRUCTION FOR BOX AND COVER EarlJ. McFadden and Norman R. Hallman, Lexington, Ky., assignors to Square DCompany, Park Ridge, 11]., a corporation of Michigan Filed Feb. 13,1964, Ser. No. 344,638 10 Claims. (Cl. 220-31) This invention relates toa box and cover having snaptogether hinge portions.

Prior to this invention, the assembling of a box and cover of similarbut unimproved construction required bending of the hinge portions ofthe box after the cover Was put in place. In accordance with the presentinvention, the cover of the improved device may be snapped intoassembled relationship with the box and no further forming operationsare required on the hinge portions of the box to secure the coverthereon.

An object of the invention is to provide an enclosure formed of asuitable material such as sheet steel and including a box and a coverwhich are provided before assembly with completely formed integral hingeportions and which are assembled without further forming operations, yetcannot be readily disconnected.

Other objects and advantages will appear when the following descriptionis considered along with the accompanying drawings in which:

FIG. 1 is a perspective view of an electrical safety switch having anenclosure constructed in accordance with the invention;

FIG. 2 is an enlarged fragmentary perspective view of the cover of theenclosure of FIG. 1 illustrating one of the hinge portions of the cover;

FIG. 3 is an enlarged fragmentary perspective view of the box of theenclosure of FIG. 1 illustrating one of the hinge portions of the box;

FIG. 4 is an enlarged fragmentary sectional view taken along the line4-4 of FIG. 1;

FIG. 5 is a view similar to FIG. 4, but showing the cover in an openposition;

FIG. 6 is a view similar to FIG. 4, but showing the cover in the processof being applied to the box;

FIG. 7 is an enlarged fragmentary view taken in the direction of arrows7-7 of FIG. 2; and

FIG. 8 is an enlargement of a portion of the cover shown in FIG. 4.

As an example of the invention, FIG. 1 shows an enclosure 10 for asafety switch. It will be obvious that the invention may be used in theenclosures of other devices.

The enclosure 10 is preferably formed of sheet metal and includes a box12 and a cover 14 each having a pair of integral hinge portionsconstructed in accordance with the invention. A side 16 of the box isprovided with an integral pair of generally U-shaped resilient hingeportions or hinge curls 18 the free ends of which preferably extendinwardly of the outer surface of the side 16 and preferably arechamfered as shown at 20-20 in FIG. 3.

A flange 22 of the cover 14 is provided with a pair of apertures 24 inwhich the hinge curls 18 are respectively received. The integral hingeportions of the cover 14 are provided by certain free end portions ofthe flange 22 adjacent the apertures 24, which portions form a pair ofhinge bars 26. Each hinge bar 26 is preferably inwardly ofliset by apair of offsetting portions 28-28 which are spaced apart sufficiently toclear the chamfered portions 20-20 of the respective hinge curl 18.

In accordance with the invention, a means is provided to enable thecover 14 to be readily connected to the box 12 without further formingoperations on the hinge curls 18. Thus, the hinge bars 26 are twisted asbest shown in FIG. 8, and are designed to have an interferingrelationship with the free ends of the hinge curls as the cover3,236,408 Patented Feb. 22, 1966 ice is being applied to the box, asbest shown in FIG. 6. It will be understood that the exact location ofthe free ends of the hinge curls 18 will vary from box to box as theboxes 12 are formed in mass production. The angle of twist of the hingebars 26 is sufficient to insure that the leading outer edges 30 of thehinge bars 26 of any cover 14 will be spaced inwardly of the free endsof the respective hinge curls 18 of any box 12 and the trailing outeredges 31 of the hinge bars 26 of any cover 14 will be spaced outwardlyof the free ends of the respective hinge curls 18 of any box 12 as thecover 14 is being applied to the box, as shown in FIG. 6. The outersurfaces 32 of the hinge bars 26 will then act as wedges to resilientlyurge the free ends of the respective hinge curls 18 outwardly as thecover 14 is being applied to the box. An angle of twist of about twentydegrees has been found satisfactory. After the hinge bars 26 have beenmoved past the free ends of the respective hinge curls 18 in a directiontoward the back of the box 12, the hinge curls resume their originalposition and the cover 14 cannot be readily removed.

Preferably the side 16 of the box is provided with a pair of outwardlyextending dimples 34. Alternatively, the flange 22 of the cover could beprovided with a pair of inwardly extending dimples. The dimples 34maintain a space between the side 16 of the box and the flange 22 of thecover after the cover is assembled on the box and thus provideadditional insurance that the hinge bars 26 will not readily come out ofthe hinge curls 18 after assembly.

\Vhile the box 12 has been shown with two hinge curls 18 and the cover14 with two corresponding hinge bars 26, it will be understood that anenclosure could also be provided with just one hinge curl andcorresponding hinge bar, or with three or more hinge curls andcorresponding hinge bars.

It will be seen that the hinge curls 18 do not have to be bent inwardlyafter the cover 14 is in place on the box 12. It is merely necessary tosnap the cover on, An extra forming operation has thus been eliminated.

Various modifications may be made in the structure shown and describedwithout departing from the spirit and scope of the invention.

We claim:

1. An enclosure comprising an open-front box having an integralresilient hinge curl formed on a side thereof, and a flanged coverpivotally mounted on said hinge curl, said cover having an aperture in aflange thereof for receiving said hinge curl and having an integralhinge bar provided by the free end portion of said flange adjacent saidaperture, said hinge bar having an interfering relationship with thefree end of said hinge curl as said cover is being applied to said boxand being twisted from the remainder of said flange sufliciently tolocate the leading outer edge of said hinge bar inwardly of said freeend of said hinge curl and to provide a wedge for resiliently urgingsaid free end of said hinge curl outwardly as said cover is beingapplied to said box.

2. An enclosure as claimed in claim 1, wherein said hinge bar isinwardly offset from the remainder of said flange.

3. An enclosure as claimed in claim 1, including means for maintaining aspace between said side of said box and said flange of said cover aftersaid cover is applied to said box.

4. An enclosure as claimed in claim 1, wherein the free end of saidhinge curl extends inwardly of the outer surface of said side of saidbox.

5. An enclosure comprising an open-front box having a plurality ofintegral resilient hinge curls formed on a side thereof and protrudingoutwardly of the remainder of said side, and a flanged cover pivotallymounted on said hinge curls, said cover having a plurality of aperturesin a flange thereof for respectively receiving said hinge curls andhaving a plurality of integral hinge bars provided respectively by thefree end portions of said flange respectively adjacent said apertures,said hinge bars having an interfering relationship respectively with thefree ends of said hinge curls as said cover is being assembled with saidbox and being twisted from the remainder of said flange sufficiently tolocate the leading outer edges of said hinge bars respectively inwardlyof said free ends of said hinge curls and to provide wedges forrespectively resiliently urging said free ends of said hinge curlsoutwardly as said cover is being assembled with said box.

6. An enclosure as claimed in claim 5, wherein said hinge bars areinwardly offset from the remainder of said flange. v

7. An enclosure as claimed in claim 5, including means for maintaining aspace between said flange of said cover and said side of said box aftersaid cover is assembled with said box.

8. An enclosure as claimed in claim 5, wherein said free ends of saidhinge curls extend inwardly of the outer surface of said side of saidbox.

9. An enclosure comprising an open-front box having an integralresilient hinge curl formed on a side thereof, the free end portion ofsaid hinge curl extending inwardly of the outer surface of said side, aflanged cover pivotally mounted on said hinge curl, said cover having anaperture in a flange thereof for receiving said hinge curl and having anintegral hinge bar provided by the free end portion of said flangeadjacent said aperture, said hinge bar being inwardly offset from theremainder of said flange, and means for maintaining a space between saidside of said box and said flange of said cover after said cover isapplied to said box.

10. An enclosure comprising an open-front box having a plurality ofintegral resilient hinge curls formed on a side thereof and protrudingoutwardly from the remainder of said side, the free end portions of saidhinge curls extending inwardly of the outer surface of said side, aflanged cover pivotally mounted on said hinge curls, said cover having aplurality of apertures in a flange thereof for respectively receivingsaid hinge curls and having a plurality of integral hinge bars providedrespectively by the free end portions of said flange respectivelyadjacent said apertures, said hinge bars being inwardly offset from theremainder of said flange, and means for maintaining a space between saidside of said box and said flange of said cover after said cover isassembled with said box.

References Cited by the Examiner UNITED STATES PATENTS 2,571,714 10/1951Henchert 22031 THERON E. CONDON, Primary Examiner.

1. AN ENCLOSURE COMPRISING AN OPEN-FRONT BOX HAVING AN INTEGRALRESILIENT HINGE CURL FORMED ON A SIDE THEREOF, AND A FLANGED COVERPIVOTALLY MOUNTED ON SAID HINGE CURL, SAID COVER HAVING AN APERTURE IN AFLANGE THEREOF FOR RECEIVING SAID HINGE CURL AND HAVING AN INTEGRALHINGE BAR PROVIDED BY THE FREE END PORTION OF SAID FLANGE ADJACENT SAIDAPERTURE, SAID HINGE BAR HAVING AN INTERFERING RELATIONSHIP WITH THEFREE END OF SAID HINGE CURL AS SAID COVER IS BEING APPLIED TO SAID BOXAND BEING TWISTED FROM THE REMAINDER OF SAID FLANGE SUFFICIENTLY TOLOCATE THE LEADING OUTER EDGE OF SAID HINGE BAR INWARDLY OF SAID FREEEND OF SAID HINGE CURL AND TO PROVIDE A WEDGE FOR RESILIENTLY URGINGSAID FREE END OF SAID HINGE CURL OUTWARDLY AS SAID COVER IS BEINGAPPLIED TO SAID BOX.